Energy Flow from Open to Closed Strings in a Toy Model of Rolling Tachyon

摘要

We study the toy model of interacting open and closed string tachyons whichdemonstrates some interesting properties of the unstable D-brane decayscenario. We compute a stress tensor of the system and study the energy andpressure dynamics. We show that the total energy of the system is conserved. Weseparate the stress tensor into two parts corresponding to open and closedstrings and study the energy flow from open to closed strings. The two vacua ofthe system could be interpreted as corresponding to the unstable D-branebackground and the open string tachyon vacuum. We study how for spatiallyhomogenous solution interpolating between these two vacua the total energy ofthe open string dissipates to the closed string.